International Council for the Exploration of the Sea Conseil International pour l’Exploration de la Mer
Palægade 2–4 DK–1261 Copenhagen K Denmark
Advisory Committee on Ecosystems ICES CM 2002/ACE:03 Ref. D, E, G
REPORT OF THE
WORKING GROUP ON ECOSYSTEM EFFECTS OF FISHING ACTIVITIES
ICES Headquarters 17–26 March 2002
This report is not to be quoted without prior consultation with the General Secretary. The document is a report of an expert group under the auspices of the International Council for the Exploration of the Sea and does not necessarily represent the views of the Council.
TABLE OF CONTENTS
Section Page
1 OPENING OF THE MEETING... 1
2 EXECUTIVE SUMMARY... 2
3 SCIENTIFIC ADVICE NEEDED BY AN ECOQ - ECOQO FRAMEWORK... 4
3.1 History and Context ... 4
3.1.1 Criteria for good Ecological Quality metrics ... 5
3.1.2 Management system needed to implement EcoQOs... 6
3.1.3 How these criteria are used in this section ... 6
3.2 Longer-term Products Required... 7
3.3 Short-term Considerations ... 8
3.3.1 Evaluation of EcoQOs ... 11
3.3.2 Possibilities to improve the performance of the EcoQ metric... 11
3.3.2.1 Commercial fish species ... 11
3.3.2.2 Seal population trends... 11
3.3.2.3 By-catch of harbour porpoises ... 11
3.3.3 Development of the scientific role of ICES in relation to the pilot project on EcoQOs ... 11
3.3.3.1 Spawning stock biomass of commercial fish species... 11
3.3.3.2 Seal population trends in the North Sea ... 12
3.3.3.3 By-catch of harbour porpoises ... 12
3.3.3.4 Proportion of oiled common guillemots among those found dead or dying on beaches 13 3.3.3.5 Changes/kills in zoobenthos in relation to eutrophication ... 13
3.3.3.6 Imposex in dogwhelks (Nucella lapillus)... 13
3.3.3.7 Phytoplankton chlorophyll a... 14
3.3.3.8 Phytoplankton indicator species for eutrophication ... 14
3.3.3.9 Winter nutrient concentrations (Dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP))... 14
3.3.3.10 Oxygen ... 14
3.4 The Medium Term ... 15
3.4.1 Issue 2 – Threatened and declining species ... 16
3.4.1.1 Convergence of threatened and declining species listing and EcoQO development... 16
3.4.1.2 The way ahead ... 18
3.4.2 Issues 3 and 4: Sea Mammals and Seabirds... 20
3.4.2.1 Marine mammals ... 20
3.4.2.2 Seabirds... 21
3.4.3 Issue 5: Fish communities... 22
3.4.4 Issue 6: -Benthic communities... 24
3.4.5 Issue 8: Habitat ... 25
3.5 Summary and Conclusions... 27
4 QUANTIFY THE RELATIVE ROLE OF FISHING AND OTHER HUMAN ACTIVITIES ON THE DYNAMICS OF THE MARINE ECOSYSTEM ... 29
4.1 Introduction... 29
4.1.1 The approach of the working group to the ToR ... 29
4.1.2 Outcome of OSPAR prioritisation ... 30
4.1.3 The Multi Criteria Approach (Resource Analysis, 1998) ... 30
4.1.4 Appraisal of the technique ... 30
4.2 An alternative approach to the quantification of impacts... 30
4.2.1 Marine aggregate dredging in the North Sea ... 31
4.2.2 Beam trawling in the North Sea... 33
4.2.3 Comparing the role of dredging and fishing activity on the dynamics of the marine ecosystem.... 34
4.2.4 Comparing the role of dredging and fishing activity on nutrient turnover... 36
4.2.5 Impact of spoil disposal on the dynamics of the marine ecosystem... 37
4.2.6 Conclusion ... 37
5 TESTING HYPOTHESES ABOUT THE SENSITIVITY OF ECOSYSTEM COMPONENTS TO BOTTOM FISHING IMPACTS... 39
5.1 Introduction... 39
5.2 Available data sets ... 40
5.2.1 Ecosystem descriptions... 40
5.2.2 North Sea surveys ... 41
5.2.3 Scotian Shelf ... 44
5.2.4 Barents Sea ... 45
5.2.5 Atlantic off the Portuguese coast ... 46
5.3 Analyses on a region-by-region basis ... 47
5.3.1 The sensitivity of the northwestern North Sea fish communities to bottom fishing impacts... 47
5.3.1.1 Introduction... 47
5.3.1.2 Analytical design ... 47
5.3.1.3 The data sets... 48
5.3.1.3.1 Groundfish survey data ... 48
5.3.1.3.2 Fishing effort data ... 48
5.3.1.3.3 Community metrics... 50
5.3.1.3.4 Species life-history characteristics ... 51
5.3.1.3.5 Species trophic level ... 51
5.3.1.4 Analysis and results ... 52
5.3.1.4.1 Effects of fishing on species richness and species diversity... 53
5.3.1.4.2 Effects of fishing on groundfish assemblage life history characteristics... 56
5.3.1.4.3 Effects of fishing on groundfish assemblage trophic structure ... 58
5.3.1.5 Discussion ... 61
5.3.2 Comparative impacts of bottom fishing on trophic structure and size composition in the North Sea ... 63
5.3.2.1 Introduction... 63
5.3.2.2 Methods to estimate metrics... 63
5.3.2.2.1 Trends in trophic level ... 65
5.3.2.2.2 Trends in biomass size spectra ... 67
5.3.2.2.3 Trends in mean weight and mean maximum weight... 69
5.3.2.2.4 Trends in biodiversity indices ... 71
5.3.2.2.5 Comparison of trends among metrics and surveys... 72
5.3.2.2.6 Assessing relationship between metrics and fishing effort... 73
5.3.2.3 Discussion ... 75
5.3.3 Scotian Shelf ... 77
5.3.3.1 Introduction... 77
5.3.3.2 Length-based data/analysis ... 77
5.3.3.3 Community metrics... 81
5.3.3.4 Conclusions... 85
5.3.4 Barents Sea ... 86
5.3.4.1 Introduction... 86
5.3.4.1.1 Species composition... 86
5.3.4.1.2 Dominant species ... 86
5.3.4.1.3 Species characteristics... 87
5.3.4.2 Analyses and results... 87
5.3.4.2.1 Biodiversity indices... 87
5.3.4.2.2 Size spectra ... 89
5.3.4.3 Future work... 89
5.3.5 Atlantic off the Portuguese coast ... 90
5.3.5.1 Introduction... 90
5.3.5.2 Data analysis ... 91
5.3.5.2.1 Average fish weight in the whole assemblage ... 91
5.3.5.2.2 Survey biomass divided into species groups... 91
5.3.5.2.3 Lmax analysis... 92
5.3.5.3 Conclusions... 93
5.4 Synthesis and Discussion ... 93
6 EVALUATING THE IMPACT OF FISHING PRACTICES ON NON-TARGET SPECIES ... 97
6.1 Introduction... 97
6.2 Evaluating impacts on non-target species ... 98
6.3 Mitigation measures... 98
6.4 Discussion... 98
7 THE DISTRIBUTION OF COLD-WATER CORAL AND THREATS FROM HUMAN ACTIVITIES... 100
7.1 Information on the distribution of cold water coral in the ICES area ... 100
7.2 Current projects on cold-water corals ... 105
7.3 Impacts on cold-water corals ... 105
7.3.1 Trawling... 105
7.3.2 Demersal longlining... 106
7.3.3 Gill and tangle netting... 106
7.3.4 Sediment input from drilling operations ... 106
7.3.5 Chemical input... 107
7.3.6 Summary... 107
7.4 Mitigation/protection of corals from human activities... 107
7.4.1 Closed areas to trawling... 107
7.5 Recommendations... 110
7.6 References... 110
8 COMPARING THE STRUCTURE OF ECOSYSTEMS ... 112
8.1 Areas to be used for ecosystem comparison ... 112
8.1.1 OSPAR regions... 113
8.1.2 Large Marine Ecosystems... 113
8.1.3 Ecological biomes/provinces ... 114
8.2 Meta-data available for comparison... 116
8.3 Conclusions... 116
9 PROPOSE A PROCESS TO DESCRIBE THE DISTRIBUTION OF SENSITIVE HABITATS AND MITIGATION OF FISHING IMPACTS... 117
9.1 Introduction... 117
9.2 Defining terms ... 117
9.3 Evaluation of the potential effects of fishing activities on sensitive habitats... 118
9.3.1 Comparing the potential impact of each fishing activity on a range of sensitive habitats ... 118
9.3.2 Mitigation measures... 119
9.4 Assessment of the effects of fishing on each habitat type... 122
9.4.1 Deep-water biogenic habitats... 122
9.4.2 Structural benthic epifauna ... 123
9.4.3 Benthic infauna ... 124
9.4.4 Mollusc beds ... 124
9.4.5 Nearshore communities ... 124
9.4.6 Intertidal mudflats... 125
9.4.7 Maerl beds... 125
9.5 Assessment of the matrix approach... 125
9.6 Developing the process ... 126
9.6.1 Incorporating ICES advice into this process... 126
9.7 Summary conclusions ... 128
9.8 Recommendations... 128
10 MAINTENANCE OF GENETIC DIVERSITY AND APPROPRIATE FORMS OF MANAGEMENT ... 133
10.1 Introduction... 133
10.2 Background... 134
10.2.1 Genetic variation among populations ... 134
10.2.2 Genetic variation within populations ... 135
10.2.2.1 The special case of small populations... 136
10.2.2.2 Case study of fisheries-induced selection on the northeast Arctic cod ... 136
10.3 Managing genetic diversity... 137
10.3.1 Management objectives ... 138
10.3.2 Reference points?... 139
10.3.3 Monitoring genetic changes... 139
10.4 Conclusions and procedural recommendations... 140
10.5 References... 141
11 ECOLOGICAL DEPENDENCE: HOW CAN THIS BE INCORPORATED INTO MANAGEMENT ADVICE?... 142
11.1 Introduction... 142
11.2 Biotic linkage... 143
11.2.1 Biological basis for linkages... 143
11.2.2 Assessing ecological dependence ... 144
11.2.3 Examples ... 145
11.2.3.1 Sandeels and predators... 145
11.2.3.2 Baltic three-species model ... 145
11.3 Biota—habitat linkages... 145
11.3.1 Biological basis for ecological linkage to habitat ... 145
11.3.2 Assessing interaction strength with the habitat ... 146
11.3.3 Examples ... 147
11.3.3.1 Herring and gravel beds ... 147
11.3.3.2 Lophelia and associated species... 147
11.4 Delivering scientific advice taking account of ecological dependence... 148
11.4.1 Possible management responses ... 148
11.4.2 How ecological linkages affect advice... 148
11.4.2.1 Generally low effect on the advice – (MSVPA) ... 148
11.4.2.2 Generally one of several considerations in the advice – (herring and gravel beds) ... 148
11.4.2.3 The dominant factor in the advice (black-legged kittiwakes and sandeels) ... 148
11.4.2.4 Developing a consistent advisory framework ... 149
11.4.3 Some practical considerations... 149
11.4.3.1 Managing for species at risk – threatened and declining ... 149
11.4.3.2 Managing vertical linkages: predator culls ... 149
11.4.3.3 Discards and offal ... 150
11.5 A workplan for ICES ... 150
11.6 References... 151
12 PROPOSED WORKSHOP ON (TOP-DOWN) ECOSYSTEM MODELS... 153
13 THREATENED AND DECLINING HABITATS: ARE THE DATA SUFFICIENT?... 154
13.1 Introduction... 154
13.2 The OSPAR selection process ... 154
13.2.1 The outcome of the questionnaire submissions (Gubbay, 2001) ... 154
13.2.2 The outcome of the Leiden workshop: Four lists of habitats in need of protection ... 155
13.2.3 Data assessment ... 156
13.3 WGECO evaluation ... 158
13.3.1 Priority list of threatened and/or declining habitats in the OSPAR Maritime Area ... 158
13.3.1.1 Carbonate mounds ... 158
13.3.1.2 Deep-sea sponge aggregation... 159
13.3.1.3 Marine intertidal mudflats... 160
13.3.1.4 Littoral chalk communities ... 161
13.3.1.5 Lophelia pertusa reefs... 163
13.3.1.6 Oceanic ridges with hydrothermal effects... 164
13.3.1.7 Seamounts... 165
13.3.2 List of threatened and/or declining species and habitats in the OSPAR Maritime Area... 166
13.3.2.1 Ampharete falcata sublittoral mud community... 166
13.3.2.2 Intertidal mussel beds... 168
13.3.2.3 Estuarine intertidal mudflats ... 169
13.3.2.4 Maerl beds... 170
13.3.2.5 Modiolus modiolus beds... 171
13.3.2.6 Ostrea edulis beds... 173
13.3.2.7 Sabellaria spinulosa reefs... 174
13.3.2.8 Sublittoral mud with seapens and burrowing megafauna... 176
13.3.2.9 Zostera beds (Z. marina, Z. angustifolia and Z. noltii)... 178
13.4 Conclusions... 179
13.4.1 Summary results of the WGECO assessment ... 179
13.4.2 Comments on the OSPAR nomination process ... 180
13.4.3 Gaps in knowledge... 181
14 FUTURE ACTIVITIES AND RECOMMENDATIONS ... 184
14.1 Recommendation: Terms of Reference... 184
14.2 Recommendation: Publication of an ICES CRR... 184
14.3 Recommendation: Provision of access to satellite vessel monitoring data ... 185
14.4 Recommendation: Habitat mapping... 185
14.5 Recommendation: Continued exploration of ecosystem metrics ... 185
14.6 Recommendation: Analytical workshops on the ecosystem effects of fishing activities ... 185
ANNEX 1: LIST OF PARTICIPANTS... 187
... 189 ANNEX 2: AGENDA
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1 OPENING OF THE MEETING
The Working Group on Ecosystem Effects of Fishing Activities (WGECO) met at ICES Headquarters, Copenhagen, from 18–27 March 2002. Attendance at the meeting comprised:
Philippe Archambault Canada
Niels Daan Netherlands
Andrey Dolgov Russia
Martin Dorn USA
Lisette Enserink Netherlands
Chris Frid (Chair) UK (England and Wales) Simon Greenstreet UK (Scotland)
Mikko Heino Norway
Louize Hill Portugal
Simon Jennings UK (England & Wales)
John Joyce Ireland
Ellen Kenchington Canada
Robert Mohn Canada
Gerjan Piet Netherlands
Jake Rice Canada
Stuart Rogers UK (England and Wales) Sigma Steingrimsson Iceland
Mark Tasker UK (Scotland) Contact details are given in Annex 1.
The Working Group members were welcomed by ICES General Secretary, Mr David Griffith. The Terms of Reference for the WGECO meeting were discussed on the first morning, and a plan of work was adopted for the meeting. Special efforts were made to make the fullest progress possible on the Terms of Reference directly supporting the advisory tasks of ICES, and to provide appropriate recommendations for the further development of work in support of those Terms of Reference where the process of arriving at a solution was begun.
Terms of Reference (C. Res 2001/2ACE02) for the meeting were:
The Working Group on Ecosystem Effects of Fishing Activities [WGECO] (Chair: Chris Frid, UK) will meet from 18–27 March 2002 at ICES Headquarters to:
a) continue the work started in 2001 to develop the scientific components needed for provision of scientific advice required by an EcoQO framework;
b) quantify the relative role of fishing activity on dynamics of the marine ecosystem and nutrient turnover, in comparison with other comparable human activities such as marine disposal, and mineral extraction, to the extent possible;
c) continue the work plan to test hypotheses about which components of the marine ecosystem are most sensitive to bottom fishing impacts;
d) in response to the EC DG Fish request for an “evaluation of the impact of current fishing practices on non-target species, … and suggestions for appropriate mitigating measures”, investigate ways to use data products produced by the Study Group on Discard and By-catch Information for ecosystem management studies [contingent on discard and by-catch from SGDBFI being available for further analyses]. Where data are sufficient, evaluate the impact of fishing on non-target species. Identify species and fisheries where mitigative actions may be warranted and, in such cases, propose and justify alternative mitigation measures;
e) drawing on material compiled by SGCOR, summarize all available information on the distribution of cold-water corals in the ICES area. Based on experience from the ICES area in particular, and more generally from cold waters of northern, southern, and deep-sea areas of the world, relate, to the extent possible, the information on the distribution of corals in the ICES area to threats from fishing activities and other potential disturbances [EC DG Fish];
f) consider the report of the former Planning Group on Comparing the Structure of Marine Ecosystems in the ICES Area and specifically advise on the areas to be used in ecosystem comparisons and the meta-data available for such comparisons;
g) propose a process to be able to summarize available information on the distribution of other sensitive habitats in the ICES area, and evaluate the adequacy of the information as a basis for scientific advice for an “evaluation of the impact of current fishing practices on … sensitive habitats, and suggestions for appropriate mitigating measures”; this should include the definition of criteria or standards for determining what is a “sensitive habitat”;
h) propose a process to be able to obtain information to develop advisory forms appropriate to the preservation of genetic diversity, beginning with the initiation of an evaluation of the advisory forms and management approaches that would be necessary and sufficient for the protection of genetic diversity of exploited stocks, and stocks suffering substantial mortality as by-catch;
i) propose a process to be able to obtain information to consider “ecological dependence in management advice, firstly addressing the groups of species with the ecological linkages that are known with high reliability to have strong ecological linkages”, including specification of the data requirements and models that would be required to provide the scientific basis for a response to that request. Propose a workplan and timetable for ICES to prepare itself for developing that scientific advice;
j) review progress of activities initiated in 2001 by the Planning Group for a Workshop on [Top-down] Ecosystem Modelling.
An additional term of reference was added shortly before the meeting, based on a new OSPAR request:
k) provide an assessment of the data on which the justification of the habitats in the OSPAR Priority List of Threatened and Endangered Species and habitats will be based; this assessment should be to ensure that the data used for producing the justification are sufficiently reliable and adequate to serve as a basis for conclusions that the habitats concerned can be identified, consistently with the Texel-Faial criteria, as requiring action in accordance with the OSPAR Strategy on the Protection and Conservation of the Ecosystems and Biological Diversity of the Maritime Area.
WGECO will report by 12 April 2002 for the attention of the ACE and the Marine Habitat, Living Resources, and Resource Management Committees.
The timing of the meeting this year allowed WGECO to overlap with the Fifth International Conference on the Protection of the North Sea (the Bergen Conference) and the meeting of the Working Group on the Application of Genetics in Fisheries and Mariculture (WGAGFM). This allowed us to fully integrate the content of the Bergen Declaration, and in particular, the adoption of a pilot EcoQO scheme, into our consideration of Term of Reference (a). In developing our thinking in respect of Term of Reference (h) we were able to use e-mail contact to seek and receive advice from WGAGFM during the course of their meeting.
Acknowledgements:
The Working Group would like to thank Marianne Neldeberg for excellent assistance, patience, and good humour in supporting our computing, system networking, and data requirement, and Louise Scharff and Vivian Piil for general logistical support and untiring assistance in a diversity of areas. It also extends thanks to Dr Jan van Delfsen (Netherlands) and Dr Siân Boyd (UK) for providing information to the group on marine aggregate extraction that would otherwise have been unavailable. WGAGFM provided invaluable help and support at the end of an e-mail link; we wish to thank them for including consideration of our activities into their already full work programme.
2 EXECUTIVE SUMMARY
This was the first meeting of WGECO on an annual cycle. We adopted this pattern to make it easier to provide timely outputs in support of ICES advisory work, and balance the workload between requests for this and the need to advance basic and applied knowledge. Once again, our workload contained a mix of requests for work in support of advice, intellectual development of work-plans to underpin future requests for advice, and original research. The Chair would like to record his thanks to all the members of WGECO for their hard work and commitment both during the meeting and in preparing for it.
Much of the workload in 2001 concerned the development and application of EcoQOs and in Section 3 we update this with a consideration of the developments that have occurred, primarily through OSPAR and the North Sea Ministerial Conference, since then. We provide some general commentary, and then focus on the work that needs to be done to provide the science base to make this approach operational following the Bergen Declaration. This work is considered in
terms of short-term, urgent, actions that are required to implement the pilot scheme and medium-term activities focused on the remaining OSPAR list of EcoQ elements associated with the 10 issues. We then consider the longer-term and more generic considerations that need to be addressed in recognition that advancing the EcoQ – EcoQO framework for the 10 OSPAR issues is, itself, only a start in the process of the adoption of the ecosystem approach to environmental management.
Back in 1992, WGECO considered the relative impact of fishing and other human activities on marine ecosystems. Our Term of Reference (b) allowed us to revisit this perennial issue and in Section 4 we provide a detailed analysis of the extent of beam trawling and dredging in the southern North Sea and some quantification of the mortality benthos suffer as a result. While it is impossible, given the data currently available, to provide a definitive answer as to the relative impacts of various activities on marine ecosystem dynamics, we have advanced our thinking on this and have made recommendations which, if implemented, will take us further forward.
In Section 5 we continue the development of our understanding of the response of ecosystems to fishing activities. This knowledge is critical in our ability to provide advice on these issues and the development of candidates for ecosystem indicators. This year our work focused on comparisons of the behaviour of various metrics in a number of geographical regions, extending across the North Atlantic from Europe to Canada, and from Portugal in the south to the Barents Sea in the north. These analyses confirm the sensitivity to changes in the ecosystem of metrics based on the size spectra of the fish assemblage. The response of some of the other metrics varied among systems, possibly in response to differences in the dynamics of the various systems, or possibly due to inherent sensitivities in the metrics to different types/structures in the data. This highlights the need for considerably more research into the behaviour of some of these metrics before they can be used in a management context. However, the size-based metrics seem to offer the hope of robust metrics.
Progress on Term of Reference (d) was constrained by the lack of appropriate data. While this was frustrating, in Section 6 we offer some considerations on the needs of recording programmes for discards of non-target species and make recommendations as to the way ICES can progress this important issue.
One of the most widely cited examples of a habitat potentially under threat from fishing activities is that of cold-water corals. In Section 7 we provide a summary of the current state of knowledge of their distribution in the ICES area, drawn primarily from the work of SGCOR, while acknowledging that the knowledge base on this is in a continual state of flux.
We then go on to look at the actual threat posed by fishing to these biogenic structures, and consider mitigation measures.
Action to protect these habitats is likely to be the subject of requests for advice in the near future. This is an area where the knowledge base is growing rapidly and so it is important that the topic is regularly reviewed and advice provided based on the latest information. We provide some recommendations to assist ICES in being prepared to provide that advice when it is requested.
Our Term of Reference (f), Section 8, also caused considerable frustration. The appropriate spatial areas or data sources for the use in ecosystem comparisons will vary depending on the nature of the questions and, until these are defined, the consideration of specification of data sets and spatial areas is premature. We provide some commentary on the work of the Planning Group on Ecosystem Comparisons and advance the consideration of spatial issues and the nature of data that might be required.
Three Terms of Reference required us to begin work on issues concerned with the provision of advice under an ecosystem approach to management. This work stems from the continued development of the ecosystem approach to management within the European Union. In September 2001 the European Commission requested that ICES begin to develop advice on: “fishing impacts on non-target species and sensitive habitats”, “the provision of protection for species ecologically dependent on species affected by fisheries” (i.e., those with strong ecological linkages) and “preservation of genetic diversity”. These are recognised as the three most immediate areas where management advice needs to adopt a wider ecosystem approach. The EC, however, emphasises in its request the need for advice about ecosystems to follow the norms of scientific development with regard to hypothesis testing and peer review. These three Terms of Reference begin that process. In each case, we were requested to use our expertise to establish exactly what framework could be applied to rigorously handle the various types of information to be assessed, where the necessary data could be found and how it should then be used. It was never the intention that WGECO would complete work on these issues at this meeting but in each case we have made substantive progress.
In Section 9, Term of Reference (g), we provide a matrix classification of sensitive habitats (taken from the OSPAR Threatened and Declining Habitats list) against fishing impacts and consider mitigation measures for each significant impact. We then review the effectiveness of this matrix approach before developing a consideration of a decision-tree approach to decision-making, and how this might be progressed as a model for preparing ICES advice on this issue.
The Convention on Biological Diversity requires the conservation of natural levels of genetic information. Predation has always been a powerful evolutionary force, altering the genetic composition of predated species; fishing is also likely to exert a selective pressure. In Section 10 we review the evidence for, and postulated effects of fishing on fish populations and then consider the framework for providing advice to address these changes. This framework is then developed in an ICES context to produce a plan for the provision of fisheries advice, including consideration of genetic effects.
Predators clearly depend on their prey, although in many cases they can switch prey should the preferred type become rare. Management of human activities using an “ecosystem approach” requires consideration of such ecological linkages – predators with their prey, species with their competitors, the habitat needs of each group of organisms. The list of such linkages is long but what is critical from a management point of view is which are important or “strong ecological linkages”, as these are the ones which need to be protected if ecosystem function and the constituent species are to be conserved. In Section 11 we develop some initial criteria for assessing linkages for their strength and then consider how management advice may need to take account of different classes of link. We then propose a means of advancing this process using the existing expertise and structures within ICES.
Section 12 briefly reviews the proposal for a Workshop on [Top down] Ecosystem Models. The Planning Group (PGEM) for this proposed workshop was established following a recommendation from WGECO in 1999 and their report was reviewed by WGECO in 2001. We now reflect on the comments of ACE on that report and the correspondence from PGEM members. WGECO remains firm in its belief that such a workshop could greatly increase the range of tried and tested tools we have available for assessing the ecosystem effects of fishing activities and in developing the ecosystem based approach to environmental management.
Section 13 deals not with one of our original terms of reference but rather attempts to address, at short notice, a request for advice to ICES from OSPAR on “threatened and declining species and habitats” in the OSPAR region. This request was directed to the Chair of ACE who subsequently asked WG Chairs to do as much as they could to assemble the necessary information. The specific request to WGECO was to consider the habitats section of the OSPAR request and
“to ensure that the data used is sufficiently reliable and adequate to serve as a basis for conclusions that the species and habitats concerned can be identified... as requiring action in accordance with the OSPAR Strategy on the Protection and Conservation of the Ecosystems and Biological Diversity of the Maritime Area”. Given the short notice, we were constrained by the information that was readily available or could easily be accessed by working group members.
However, we recognised the importance of providing this analysis in order to assist ICES in formulating advice to OSPAR and so gave this work a high priority. We have therefore assessed each habitat and given an opinion on the adequacy of the information base used, and that available, in determining its status with regard to both “threatened” and
“declining” in the OSPAR region. This information is presented in a standard format to aid comparison and extraction of information on a particular habitat.
Traditionally our reports contain a more wide ranging section, entitled Food for thought, that has provided us with an opportunity to include material and ideas developed at the meeting but not immediately germane to one of the Terms of Reference. This section does not appear in this report, not because we had no ideas to develop but simply the workload provided by our eleven Terms of Reference completely filled our time. In Section 15 Future Activities and Recommendations we include a number of recommendations for consideration by ICES. In addition to these broad recommendations, many of our Sections also include specific recommendations for advancing those particular areas of work.
3 SCIENTIFIC ADVICE NEEDED BY AN ECOQ - ECOQO FRAMEWORK 3.1 History and Context
Term of Reference a) states “continue the work started in 2001 to develop the scientific components needed for provision of scientific advice required by an EcoQ – EcoQO framework”.
This work took on greater importance and urgency during the WGECO meeting, as the Fifth International Conference on the Protection of the North Sea, comprising North Sea Ministers and members of the European Commission responsible for protection of the environment, adopted the Bergen Ministerial Declaration on 21 March 2002. A number of important provisions of the Bergen Declaration are relevant to the interests and past activities of WGECO. The Declaration is consistent with many science initiatives that WGECO has been promoting throughout its 12 years of activity, and brings into focus the need for much more science activity in these areas at this meeting and in meetings to come.
With regard to this specific Term of Reference, Paragraph 2 of the Bergen Ministerial Declaration agrees to “implement an ecosystem approach to the health of the North Sea ecosystems” and that “management will be guided by the
conceptual framework” in Annex 2 of the Declaration. The conceptual framework in Annex 2 goes far beyond the activities within the competence of WGECO (including policy decisions, control and enforcement). However, within the scientific components of the framework, explicit objectives play a central role. Correspondingly, Annex 3 of the Declaration lists a set of Ecological Qualities (EcoQs), Ecological Quality Elements, and Ecological Quality Objectives (EcoQOs) that are an opening step in implementing the commitments to an ecosystem approach that are made in the Bergen Declaration. WGECO has been considering the issue of operational ecosystem objectives during several meetings, and takes this Term of Reference as linked directly to the EcoQ – EcoQO aspects of the much larger
“conceptual framework for an Ecosystem Approach”. For the remainder of this section, we refer to the “EcoQ – EcoQO framework” as the much more restrictive job of identifying, justifying and using EcoQs, EcoQ elements, and EcoQOs, as presented in Annex 3 of the Bergen Declaration. There are other contributions that WGECO could make to the much larger conceptual framework, but they are outside the material needed to address this Term of Reference.
While applauding the important step forward represented by the Bergen Declaration, WGECO stresses that last year’s evaluation of the EcoQ – EcoQO framework found loose ends, loose language, and loose thinking to be pervasive in many documents about EcoQs, EcoQOs, etc. In Section 5 of last year’s report, WGECO attempted to provide more systematic rigour and direction to the selection and implementation of EcoQs and EcoQOs, as well as suggestions for clearer terminology. These concerns have been addressed to varying extents, and the terminology and argumentation are improved in the background documentation prepared by OSPAR for the Bergen Meeting (OSPAR, 2002). However, the developments over the past year have increased the importance of strengthening the scientific framework for EcoQs and EcoQOs, and making it more operational. WGECO still thinks that without substantial improvements in rigour of the EcoQ – EcoQO framework, there is still a risk that the EcoQ – EcoQO framework may achieve no more than past scientific advisory and management frameworks. Therefore, WGECO welcomes the opportunity to build on the work reported last year, with the more specific focus of the Bergen Declaration.
Throughout Section 5 of ICES (2001a), WGECO provided guidance on a number of aspects of a scientifically sound and operationally effective EcoQ – EcoQO framework for the science and management of marine ecosystems. These points were accepted by the Advisory Committee on Ecosystems (ACE), and comprise much of the material in Section 4 of the 2001 ACE Report (ICES, 2001b). We repeat that guidance here in Section 3.1.1, as a starting point for further development in this report. We do not repeat the rationales for our various conclusions and recommendations, where they were developed adequately in the previous report. Following presentation of that information, we step to the long-term perspective. Without intending to diminish the importance of the commitments in the Bergen Declaration, Section 3.2 gives emphasis to the scope of the job remaining, if the EcoQ – EcoQO framework is really to become a comprehensive framework for protection of the North Sea.
For the EcoQOs actually specified in Annex 3 to the Bergen Declaration, the commitment is to move forward immediately with a pilot project. In Section 3.3, below, we consider how well prepared the scientific community is to proceed immediately with implementation of those specific EcoQOs, and what role ICES and WGECO could have in ensuring rapid but sound progress. Several EcoQ elements in Annex 3 to the Bergen Declaration do not have specific EcoQOs, and in those cases the Declaration states the intent to proceed with EcoQOs for them within the next two years.
Section 3.4, below, considers the status of scientific knowledge relative to those EcoQ elements, and identifies gaps in the scientific basis for relevant EcoQOs. Where gaps are found, we provide guidance on how to address them and the possible roles for ICES and WGECO. Both sections are quite detailed, as they try to provide clear descriptions of necessary work, but differ in the time scale for the necessary actions. Throughout this entire section, we do our best to avoid second-guessing the choices of EcoQ elements and EcoQOs, and offer constructive suggestions for moving ahead, given Annex 3 of the Bergen Declaration.
3.1.1 Criteria for good Ecological Quality metrics
Deriving from several sources (Anon., 1999; Lanters et al., 1999; Kabuta and Enserinck, 2000; ICES, 2001c, 2001d; Piet, 2001), WGECO identified several key features of EcoQ metrics. These were explicitly identified as neither necessary nor sufficient conditions for an EcoQ and corresponding EcoQO to be useful. In particular circumstances, one or more could be missing from a useful EcoQ – EcoQO, or some additional properties might be considered important. Nonetheless, they were considered excellent properties to use in screening potential EcoQs and EcoQOs. The more properties from this list that a candidate EcoQ and corresponding EcoQOs lacked, the more likely that the EcoQO would not be a practical and effective guide to actions by managers. If an EcoQO is ineffective at guiding management decision- making, it is not likely to contribute to better protection of marine ecosystems and more sustainable uses of them.
As reported in Section 5.3.2 of the 2001 WGECO report (ICES, 2001a), metrics (features that are “elements” in the sense of the Bergen Declaration when stated factually, and EcoQOs when stated quantitatively with a reference point) of EcoQs should be:
• relatively easy to understand by non-scientists and those who will decide on their use;
• sensitive to a manageable human activity;
• relatively tightly linked in time to that activity;
• easily and accurately measured, with a low error rate;
• responsive primarily to a human activity, with low responsiveness to other causes of change;
• measurable over a large proportion of the area to which the EcoQ metric is to apply;
• based on an existing body or time series of data to allow a realistic setting of objectives.
In addition an EcoQ metric may:
• Relate to a state of wider environmental conditions.
The background documentation on EcoQOs for the Bergen Declaration (OSPAR, 2002) does not comment on these criteria explicitly. However, commentary on the Purpose and Use of EcoQOs, particularly Parts I.1.7, I.1.9, I.5 and I.6, are consistent with the importance of the criteria adopted by WGECO. Although the criteria were not used in screening the EcoQOs in Table B, Annex 3 of the Bergen Declaration, the text in Appendix I of OSPAR (2002) illustrates that the authors of the Declaration were considering factors similar to those that led to the WGECO criteria, if perhaps in a less systematic way.
3.1.2 Management system needed to implement EcoQOs
Last year’s WGECO report (ICES, 2001a) also noted that just having EcoQs and EcoQOs, however well selected, was no assurance of progress towards better protection and more sustainable uses of marine ecosystems. The management system has to use the EcoQOs, and advice provided within an EcoQ – EcoQO framework. WGECO was pessimistic about the prospects for the current management and decision support systems to use the EcoQ – EcoQO framework any more effectively than it used current (and preceding) frameworks for bringing outcomes of fishing into correspondence with goals of protection of ecosystem health and sustainability of uses. To address this problem, in Section 5.1.4.2 (of ICES, 2001a) we noted several necessary attributes of a management system, if it was to use EcoQs and EcoQOs as effective tools in the protection of marine ecosystem health and the achievement of sustainable usage of marine ecosystems:
a) Institutional mechanisms are required to reconcile real or perceived incompatibilities among different objectives, whether they are objectives for fisheries contrasted with integrated objectives for ecosystem quality, or even ecological, economic, and social objectives for any specific use, including (but not exclusively) fishing.
b) For the monitoring and assessment of different EcoQs, it is important to establish a peer review and advisory framework that deals explicitly with quality control of data collection and analysis.
c) For particular metrics used to evaluate an EcoQO, the historic hit, miss, and false alarm rate of the metric should be explicitly examined, and the performance of the metric over time evaluated.
d) It could be argued that it is necessary to protect countless properties of ecosystems, and processes have to be developed to identify which ones should receive direct consideration.
e) Methods need to be developed to ensure that advice is effective in supporting decision-making when progress on achieving numerous individual objectives is uneven.
f) Methods need to be developed to relate specific human activities unambiguously to status relative to specific EcoQOs.
These are relevant considerations in the medium and longer term, as we move from debate about selecting EcoQ elements and EcoQOs to actually using them in management, or even expanding the current pilot tests of Table B, Annex 3 EcoQOs to the whole EcoQ – EcoQO framework, rather than just individual bits of it.
3.1.3 How these criteria are used in this section
The remaining subsections of Section 3 address the EcoQ – EcoQO framework on three time scales: long-term, medium- term, and short-term. These should not be considered an ordering of the sequence in which necessary actions should be inaugurated. Work should be started at the earliest opportunity to make progress on all three time scales. In fact, work
relevant to some of the longest term considerations has been on-going for years, inside and outside of WGECO, and must be continued if only with greater urgency. Rather, the three time scales are when the products of the activities are needed.
The long-term products will be needed only when evaluation of the pilot projects called for in the Bergen Declaration are completed and the scope of the EcoQ initiative is ready to grow from pilot to implementation stages (around 2006–2008).
The short-term products are needed almost immediately, for any progress to be made even on the pilots. The medium- term products will be needed in the next 12–18 months (~2003), for additional testing, as in the current pilot projects, to include the EcoQ elements in Annex 3, Table A (Bergen Declaration) that do not yet have corresponding EcoQOs in Table B.
3.2 Longer-term Products Required
The commitments reflected in paragraph 2, and elsewhere in the Bergen Declaration, promise a more inclusive management approach to the North Sea. WGECO particularly welcomes the commitment to immediate action to move ahead on these strategic commitments, as reflected particularly in paragraph 4iii) and associated Annexes 2 and 3. The pilot projects to be run are an appropriate first step to bringing those commitments into practice. However, it must also be acknowledged that the pilots in the Annex are just that: pilot projects of how to go about the job of setting EcoQOs for EcoQs, and monitoring status and progress against them. Consistent with the discussion in Section 7 of last year’s report (ICES, 2001a) and Section 3.3 here, the selected EcoQOs are generally among the most simple properties that might be informative about EcoQs, and the EcoQs are among the more simple ecosystems properties for which monitoring, evaluation, and reporting can be undertaken. Starting simple is appropriate for a pilot project. However, even if there were to be successful pilots for all the EcoQs in Table A, at that point the EcoQ–EcoQO framework would be very far from “a coherent and integrated set of Ecological Quality Objectives” (Paragraph 4, Bergen Declaration). This, in turn, leaves the science, management, and policy communities far from a framework adequate to implement an ecosystem approach to “manage all human activities that affect the North Sea, in a way that conserves biological diversity and ensures sustainable development” (Paragraph 1, Bergen Declaration).
The Background Document for the Development of EcoQOs for the North Sea (OSPAR, 2002), which was used in the preparation of the Bergen Declaration, also notes that much work remains to be done on EcoQs and EcoQOs. It specfies in its opening text that “There are further objectives relating to a number of issues, where progress has been made, but where further work is required to complete them” (introduction text). Even for EcoQOs which are referred to as “in an advanced stage of development” (paragraph 10), OSPAR points out that the overall work is far from complete. For example, under the EcoQO for Proportion of Oiled Common Guillemots, it is noted that “Oil pollution that affects seabirds comes from a variety of sources … All of these sources of oil will need to be addressed” (Appendix 1, Section 4.1). Under the EcoQO for Commercial Fish Species, it is noted that “In the longer term [it is necessary to] develop biologically and ecologically based target reference levels as a basis for management objectives” (Appendix 1, Section 1.1) (OSPAR, 2002).
WGECO has repeatedly stressed the complexity and scope of the job necessary to have EcoQs sufficient to support the ecosystem approach comprehensively, and how incomplete the scientific ability is at present to support a full suite of EcoQs. At the end of our evaluation of a much larger set of candidate EcoQ elements than is represented in Table A, Annex 3 of the Bergen Declaration, we concluded that “there is a real need for additional development and testing of several metrics described here. There are some components of the ecosystem for which we do not have adequate measures. In the long-term, there is a need for the development of new metrics to describe these key ecosystem qualities”
(Section 7.5.4) (ICES, 2001a). Among the ecosystem components for which there were no adequate measures were properties as important as biological diversity, ecological functionality, and spatial integrity. Each of these properties is quite broad, and will require a number of EcoQs to address comprehensively the protection of the entire North Sea and sustainability of all uses of it. Many of the other properties of marine ecosystems that WGECO was able to consider in last year’s report are not covered by any of the EcoQs and EcoQ elements in Annex 3, and these must all be brought into the EcoQ – EcoQO framework.
Even properties which are included in Annex 3, and which may appear relatively straightforward, such as “commercial fish species”, or a “low level (<2) of imposex in female dogwhelks”, require a great deal more work. At present, limit and precautionary biomass reference points for commercially exploited fish stocks have, in almost all cases, been based solely on single-species considerations (ICES, 2001f, 1998) and ignore relationships such as age-size-fecundity (Marshall et al., 1999), spatial and genetic population structure (Section 10, below), and environmental forcing factors (GLOBEC). For an EcoQ – EcoQO-based framework to have a high likelihood of ensuring protection of even commercially exploited species as components of marine ecosystems with important structural and functional roles, all these considerations will eventually have to be addressed. Imposex level in dogwhelks is a good measure of TBT in local areas, but TBT is only one of many contaminants that impact ecosystem health, and its use will soon be banned in the North Sea (C. Frid, pers.
comm.). Other EcoQ elements and EcoQOs are necessary for the effects of contaminants to be captured in the EcoQ – EcoQO framework.
WGECO, ICES, and the larger community will be monitoring progress on the pilot projects for at least two reasons. The first reason is as a test of the effectiveness of the EcoQ – EcoQO framework as a measurement and evaluation tool. Can technical experts (scientists and their co-workers) actually identify and justify reference levels, measure status and trends relative to the reference points, and provide sound risk-based advice using EcoQOs? Does the EcoQ – EcoQO framework clearly inform all stakeholders of the questions posed and answers found by the technical experts, and more generally, of the state of the ecosystem relative to their interests and values? Finally, does the EcoQ – EcoQO framework provide clear guidance to managers and decision-makers relative to the decisions for which they must take responsibility, the options available to them for each decision, and the consequences of each option for ecosystem conservation and sustainability of activities. It is expected that the effectiveness of the EcoQ – EcoQO framework will evolve over time, as, for example, the framework of providing fisheries advice within a precautionary approach has evolved within ICES (ICES PAWG report 1997, 2001). However, the pilot projects should provide some indication of at least whether the EcoQ – EcoQO framework is a promising pathway to improved advice, improved decision-making, and improved public understanding.
The second reason to monitor the progress of these pilot projects closely is as a test of the commitments of governments and agencies to use the EcoQs as a basis for management action. Even if the EcoQ – EcoQO framework is an effective tool, to be worthwhile the tool must be used for improving decision-making about the uses of marine ecosystems, including, but not restricted to, fishing. This cannot be a formal test, of course, because there are numerous reasons why marine ecosystems (and the Ecological Quality elements captured in the EcoQOs) may change, and not all of them may be the result of decision-making based on the EcoQ – EcoQO framework. Nonetheless, the pilot projects have to be informative about the role of the new EcoQ – EcoQO framework, and its constituent tools, in decision-making. If it appears that the tool is not used, one must ask what justification there is to invest the large amount of scientific effort that will be required to make the EcoQ – EcoQO framework adequately comprehensive. Remembering that the pilot projects soon to be under way from Table B, Annex 3 are among the simplest cases, if the EcoQ – EcoQO framework is going to result in noticeable improvements in the ecosystem properties targeted by EcoQ elements, it should do so in these simple cases. If not, the EcoQ – EcoQO framework can hardly be expected to lead to major gains in ecosystem protection and sustainability of uses when the management tasks are made much more complex: more EcoQOs to satisfy simultaneously, demanding action on the basis of ecosystem properties less convincingly linked to direct benefits, etc.
IF the EcoQ – EcoQO framework seems to be effective, and IF the institutional buy-in is strong enough that progress seems to be being made, the scientific community is expected to be active in developing the more comprehensive suite of EcoQs and EcoQOs that we believe necessary. From the reports produced over the past twelve years, WGECO feels that it has demonstrated that it has important contributions to make to these scientific tasks, adding the necessary complexity and completeness, while keeping the whole suite of EcoQs and EcoQOs operational and realistic.
Recommendation from WGECO to ACE and MCAP: WGECO should be identified as the lead Working Group to coordinate the scientific input needed for advisory support to the developing EcoQ – EcoQO framework. Some of this coordination will be through work done by WGECO, and some through evaluation against consistent standards and integration of work done in other Working and Study Groups.
3.3 Short-term Considerations
The Ministers signing the Bergen Declaration in March 2002 have adopted ten EcoQOs (Table 3.3.1) for immediate application as a North Sea pilot project within the framework of OSPAR. The pilot project will:
a) assess the information that is, or can be made, available in order to establish whether the EcoQOs are being, or will be, met. Where the EcoQOs are not being met, the information will be used to determine the reason. Costs and practicability should be taken into account in deciding what information can be made available;
b) where an EcoQO is not being met, review any policies and practices which are contributing to that failure; and c) if needs be, reconsider the formulation of such EcoQOs (Paragraph 4iv, Bergen Declaration).
Plainly, in order to assess whether or not an EcoQO is being met, there is a need to establish monitoring schemes. The Ministers thus agreed to establish coherent monitoring arrangements, in order to enable progress towards meeting the EcoQOs to be assessed. These arrangements will be integrated into the OSPAR Joint Assessment and Monitoring Programme (Bergen Declaration, Paragraph 4v).
Table 3.3.1. Ecological quality elements and objectives agreed by North Sea Ministers at Bergen, March 2002 (from Annex 3, Table B, Bergen Declaration). Further background information on each element/objective may be found in OSPAR (2002).
Ecological quality element Ecological quality objective
(a) Spawning stock biomass of commercial fish
species Above precautionary reference points1 for commercial fish species where these have been agreed by the competent authority for fisheries management (c) Seal population trends in the North Sea No decline in population size or pup production of ≥10 % over a period
of up to 10 years
(e) By-catch of harbour porpoises Annual by-catch levels should be reduced to levels below 1.7 % of the best population estimate
(f) Proportion of oiled common guillemots among those found dead or dying on beaches
The proportion of such birds should be 10 % or less of the total found dead or dying, in all areas of the North Sea
(m) Changes/kills in zoobenthos in relation to eutrophication2
There should be no kills in benthic animal species as a result of oxygen deficiency and/or toxic phytoplankton species.
(n) Imposex in dogwhelks (Nucella lapillus) A low (<2) level of imposex in female dogwhelks, as measured by the Vas Deferens Sequence Index
(q) Phytoplankton chlorophyll a2 Maximum and mean chlorophyll a concentrations during the growing season should remain below elevated levels, defined as concentrations >
50 % above the spatial (offshore) and/or historical background concentration
(r) Phytoplankton indicator species for eutrophication2
Region/area-specific phytoplankton eutrophication indicator species should remain below respective nuisance and/or toxic elevated levels (and increased duration)
(t) Winter nutrient concentrations (Dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP)) 2
Winter DIN and/or DIP should remain below elevated levels, defined as concentrations > 50 % above salinity-related and/or region-specific natural background concentrations
(u) Oxygen2 Oxygen concentration, decreased as an indirect effect of nutrient enrichment, should remain above region-specific oxygen deficiency levels, ranging from 4–6 mg oxygen per litre
Notes:
1In this context, “reference points” are those for the spawning stock biomass, also taking into account fishing mortality, used in advice given by ICES in relation to fisheries management.
2The ecological quality objectives for elements (m), (q), (r), (t) and (u) are an integrated set and cannot be considered in isolation. ICES will give its further advice during the implementation phase.
Many of these EcoQOs either correspond to, or address ecological features similar to, potential EcoQs discussed in Section 7 of last year’s report (ICES, 2001a). In some cases, concerns raised last year remain relevant to the EcoQOs that have been selected for the pilot project, and in some other cases the EcoQO selection raises new concerns relative to our criteria (Box 3.1).
Box 3.1. Detailed comments on individual EcoQOs from the Bergen Declaration, Annex 3, Table B.
Spawning stock biomass of commercial fish species
Precautionary fishing mortality rates are implicitly included in this objective according to the footnote in the Bergen Declaration. The use of the word “above” is confusing and might better be replaced by “beyond”. The description in the background document only refers to biomass reference points and the text should therefore be amended.
Seal population trends in the North Sea
The background document does not specify whether the objective applies to the total North Sea stocks of grey seals and common seals, respectively, or to largely reproductively isolated sub-populations. This needs to be resolved. It is by no means clear how the objective must be interpreted: a decline > 10 % within a single year would obviously not meet the objective, even when it is followed by an increase. Moreover, the objective would allow for, e.g., a 40 % decrease over a 50-year period, if only the condition is met that the decline is so gradual that it does not exceed 10 % within 10 years.
By-catch of harbour porpoises
There is a potential statistical problem, because the objective does not state the probability for any estimate being below 1.7 %. The North Sea harbour porpoise population may have some sub-divisions; further research is under way to resolve this issue. The current EcoQO for the North Sea assumes a unit stock; adjustments would be required in the light of emerging research results.
Proportion of oiled common guillemots among those found dead or dying on beaches
The background document clearly states that this objective does not refer to specific localities or events, but to monitoring records integrated over areas and time. It is by no means clear which areas are distinguished or whether the temporal unit is season or year.
Changes/kills in zoobenthos in relation to eutrophication
This objective might put unrealistic demands on monitoring efforts, unless some kind of warning system could be developed to trigger extensive survey activities.
Imposex in dogwhelks (Nucella lapillus)
This is also a completely open-ended objective that might require sampling at every location where dogwhelks might occur.
The Ministers noted that ICES should collaborate with OSPAR to review progress on the pilot projects testing the EcoQOs in Table 3.3.1 (Paragraph 4vi), but gave no details for roles and responsibilities. ICES can offer scientific advice and input at several stages of the short-term EcoQO process. First, as explained last year (Section 5.3 of ICES, 2001a) all of the adopted EcoQOs for the pilot project should be evaluated against the criteria outlined in Section 3.1.1, above.
Some of the EcoQOs were considered in 2001 by WGECO (ICES, 2001a), and these considerations are repeated below, with some further development. We continue to recommend that the other EcoQOs undergo the same evaluation, and note that other Working Groups should provide their input to this process.
Secondly, ICES, through the expertise of its Working Group and advisory process, could have a role in coordinating the monitoring required for many of the EcoQOs and/or in evaluating the results of this monitoring. Some input would have broad and general value, such as the advice on trend monitoring in Annex 9 of the 2001 ACME Report (ICES, 2001e).
There are also many more specific opportunities for ICES involvement in the work associated with individual EcoQOs, as given below.
3.3.1 Evaluation of EcoQOs
In 2001, WGECO graded the various possible metrics for properties covering key ecological qualities (ICES, 2001a).
Table 3.3.1.1 repeats this analysis for the ten EcoQOs selected in Annex 3, Table B of the Bergen Declaration.
3.3.2 Possibilities to improve the performance of the EcoQ metric 3.3.2.1 Commercial fish species
Measurement of spawning stock biomass is subject to a number of errors and biases that are well known to relevant ICES working groups and to advisory committees. ICES is continually striving to improve the situation in order to provide better fish stock advice; these improvements will help improve the performance of the EcoQ metric.
Fish stocks will always be responsive to natural factors that cannot be controlled. Understanding of the effects of these natural factors will improve through time, but full understanding is unlikely to be achieved in the near future, if ever.
3.3.2.2 Seal population trends
It is not known how sensitive seal populations are to human activities apart from direct killing, either deliberately or through fisheries by-catch (where the linkage can be modelled and is relatively tight). However, this EcoQO is designed to act as a trigger for further research to determine whether manageable human activities are the cause of any future decline. In the meantime, research on aspects of the interaction between humans and seals will continue, for instance, on establishing cause-effect relationships between pollutants and seal population health. The greatest recent cause of negative change in seal populations was due to an epizootic; the degree to which this was an indirect result of chemical pollution is the subject of debate and research.
3.3.2.3 By-catch of harbour porpoises
Harbour porpoise by-catch is not easy to measure accurately, as it requires the deployment of independent observers on reasonable proportions of the fleets causing the by-catch. In general, recommended methods are being used in the two existing schemes (UK and Denmark) that are examining harbour porpoise by-catches in the North Sea. Norwegian by- catches have never been monitored using reliable methods. In addition, monitoring of small-boat fisheries is problematic everywhere, and the results are less comprehensive than for the fisheries using larger boats. In all cases, greater monitoring effort is required if annual figures are to be used. This is also required for EU member states under the Habitats Directive.
3.3.3 Development of the scientific role of ICES in relation to the pilot project on EcoQOs
WGECO has expertise on the matters addressed by the selected EcoQ metrics. Broadly, once an EcoQ metric has been decided, science can help in defining the current level of that metric, reconstructing the historical trajectory of that metric, and in establishing and conducting a scientifically robust monitoring programme. Monitoring information, or other research information, might be used to determine what management actions could be taken to help meet the EcoQO, particularly when placed in the context of historical values of the metric. WGECO has applied its expertise to some of the pilot project EcoQOs to illustrate the role that ICES might play in future.
Obviously, WGECO is not the only Working Group within ICES with expertise in the scientific disciplines relevant to the EcoQOs in Table 3.3.1. Input should also be encouraged from other appropriate Working and Study Groups.
However, we encourage that the evaluation framework tested and adopted by WGECO be used widely, and that the role of ICES in the EcoQ initiative continue to build on the experience of WGECO in provision of the scientific basis for ICES advice on ecosystem impacts of human activities. For example, the experts in the Working Group on Seabird Ecology (WGSE) and the Working Group on Marine Mammal Population Dynamics and Habitats (WGMMPH) (see Sections 3.3.2.2–3.3.2.4, below) are generally not from institutes presently supported by governmental funds for participation in ICES. Thus, although their expertise is very relevant, there are relatively fewer guarantees of participation in ICES meetings by these experts. ICES and its North Sea Member Countries might need to address this issue if they wish to attract EcoQO-related work in future.
3.3.3.1 Spawning stock biomass of commercial fish species
ICES is currently the source of scientific advice on the current and historical Spawning Stock Biomasses (SSB) for commercially exploited species in the North Sea. Notwithstanding the criticisms that have been directed at ICES advice
on SBB (and fishing mortality) as inaccurate and imprecise (letter from the EU addressed by MCAP), ICES advice has been a reliable basis for management decision-making (see ICES Strategic Plan, ICES website). ICES has also introduced a number of quality assurance steps to its methods for estimating stock status, including SSB, and sources of error and bias, when they occur, are generally understood (ICES, 2002a, 2002b). ICES has also considered the value of Blim and Bpa
as EcoQO reference levels, and found them to be appropriate (ICES, 2001b). As long as the ICES intent that management decision-making keep stocks above Bpa with high probability is achieved, such an approach is consistent with the intent of using EcoQs and EcoQOs to maintain healthy marine ecosystems.
WGECO recommends that ICES continue to be the source for scientific advice on current and historical SSB for exploited fish stocks, and supports strongly the implementation of further quality control measures, as they are identified.
ICES has also advised routinely on management measures to increase SSB when necessary. WGECO interprets the commitments in the Bergen Declaration (Section III – Sustainable Fisheries) as a mandate to increase the scope and clarity of such recommendations, with ACFM receiving input from groups such as WGECO, as well as the assessment Working Groups, when developing its advice.
3.3.3.2 Seal population trends in the North Sea
WGMMPH and its predecessors have periodically assessed seal populations of the North Sea and are the only existing international group in a position to do this. Therefore, WGECO recommends that ICES be tasked to lead the scientific implementation of this EcoQO, collating, evaluating, and integrating the census efforts of the various countries around the North Sea. The majority of grey seals in the North Sea haul out on UK coasts and are monitored by an annual programme, using standardised methods, conducted by the Sea Mammal Research Unit. Harbour seals occur in approximately equal numbers on continental coasts and UK coasts. They are not monitored annually on UK coasts, but are monitored elsewhere. Methods are standardised. Less is known about the causes of changes in seal populations, but some projects suggested and fostered by WGMMPH will help in determining the effects of contaminants on seal populations. The Working Group could also suggest and foster projects to examine other factors that might contribute to changes in seal populations. All monitoring must obviously reflect the defined stock structure. As specific tasks, ICES could publish a) a standardised seal censusing manual, and b) an annual report on the state of North Sea seal populations.
3.3.3.3 By-catch of harbour porpoises
WGMMPH and its predecessors have reviewed small cetacean by-catch on two occasions, most recently in 2001 (ICES, 2001b). Again, WGECO recommends that ICES be tasked to lead the scientific implementation of this EcoQO, collating, evaluating, and integrating the census efforts of the various countries around the North Sea. In 1998 WGMMPH also reviewed methods for monitoring such by-catch, and recommended protocols for producing reliable results. Failure of countries to allocate greater effort to monitoring harbour porpoise by-catch will mean that the status of, and progress with, this EcoQO will be impossible to evaluate reliably.
The metric also requires assessment of by-catch against an overall population figure; the figure currently in use derives from surveys in 1994, so there is a need to update this in the near future. Plans to repeat the survey in 2003 or 2004 are being made at present. Methods are reasonably standardised by the IWC Scientific Committee and WGECO recommends that the protocols recommended by the IWC Scientific Committee be followed.
Management action to reduce by-catch could be through: a) time/area closures, b) modification of fishing gear, or c) overall effort reduction. All of these actions require knowledge of fishing fleets, including the number of vessels, fishing methods, fishing areas, and measures of fishing effort. ICES requires such information on effort for many advisory roles that it undertakes, but WGECO and other groups have failed consistently to obtain this information. Advice on the appropriateness and effectiveness of options for mitigation measures has been sought of, and provided by, ICES in recent years, and we do not consider it a priority to revisit this advice in the near future.
